This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Objective: To determine the accommodative ability in older rhesus monkeys following central stimulation before and after lens lasering. RESULTS: Currently, monkeys that received laser treatment of the lens are being housed for long-term observations. Previously, an electrode was implanted into the Edinger- Westphal nucleus of each of 2 older rhesus monkeys so that accommodation could be stimulated centrally. In addition, 4 young rhesus monkeys were used as test subjects to calibrate the femtosecond laser. Baseline testing was completed prior to determination of the effects of lens lasering on the accommodative response. The femtosecond laser procedure appears to be well tolerated in the monkey eye. However, small retinal burns (1-2 mm in size) were noted in 2 out of 5 monkeys lasered. The ability to obtain refractive measurements with the Hartinger coincidence refractometer was not compromised by the femtosecond laser procedure beginning 24 hours after lasering. Animals did not exhibit abnormal behavior or evidence of pain or discomfort. Slit lamp examinations are performed bi-annually in the remaining four rhesus monkeys. All animals maintain normal vision. Presently the animals continue to be monitored and future experimental plans are being considered. This research used WNPRC Animal and Pathology Services.